'Fieldfare' was a British operation by the Special Operations Executive to reconnoitre the railway linking Åndalsnes and Dombås in German-occupied Norway, prepare weapons and explosives dumps near the railway, and prepare plans to counter German defensive measures along the railway (7 March 1944/8 May 1945).
The three-man party, comprising J. Rønneberg, B. Strømsheim and O. Aarsæther was delivered by air into Norway on the night of 7/8 March, but lost much of its equipment in a bad landing. The party received further supplies in July but had to survive until the liberation on meagre rations. The party undertook its sole action against the railway on 5 January 1945. In March 1945, Rønneberg travelled back to the UK but returned in May to help in the liberation of Ålesund.